Various products are fabricated in a continuous production line by the sequential addition of components to previously supplied components. One such continuous production process is the construction of disposable absorbent articles such as training pants, diapers, incontinence devices, etc., where components such as mechanical fasteners are assembled as part of the article in the production process. Mechanical fasteners, particularly hook and loop type fasteners not only form part of the finished article, but must be properly aligned during folding of the components of the article so that the finished article, such as a training pant, will stay fastened when placed on a wearer.
Garments, and more particularly disposable absorbent garments, have numerous applications including diapers, training pants, feminine care products, and adult incontinence products. A typical disposable absorbent garment is formed as a composite structure including an absorbent assembly disposed between a liquid permeable bodyside liner and a liquid impermeable outer cover. These components can be combined with other materials and features such as elastic materials and containment structures to form a product which is specifically suited to its intended purposes. A number of such garments include fastening components which are intended to be secured together (e.g., pre-fastened) during manufacture of the garment so that the product is packaged in its fully assembled form.
For example, one such pre-fastened garment is a child's training pants, which have a central absorbent chassis and front and back side panels extending laterally out from the chassis adjacent longitudinally opposite ends thereof. Each of the front and back side panels has a fastening component thereon, such as a hook or a loop fastener. During manufacture of the training pants, the central absorbent chassis is initially formed generally flat and then folded over so that the front and back side panels face each other. The respective fastening components of the front and back side panels are then aligned and engaged with each other to pre-fasten the training pants in its fully assembled three-dimensional form.
However, existing techniques for making conventional garments such as the training pants described above or other pre-fastened garments which engage fastening components together during manufacture are in some respects inadequate. For example, weak engagement strength between hook and loop fasteners, partial or whole separation of the fastening components during manufacture and packaging problems resulting from poorly fastened or otherwise unfastened components may be some of the shortcomings of existing pre-fastened garment making techniques. If, for example, the hook and loop fastening components are not properly aligned so that they have the necessary engagement as the result of the hook and loop fastening components being laterally misaligned when the garment is folded, the garment may not stay fastened unless the hook and loop fastening components are re-fastened by hand which might be perceived by a customer as a defective product. There is a need, therefore, for apparatus and methods which can determine at a point in the production cycle if, for example, a folded garment has the proper alignment between fastening components or should be rejected.